WAKEFIELD, N.H. (WPRI) — First responders are reminding everyone to make sure their carbon monoxide detectors are working properly after four New Hampshire residents were discovered dead inside their home on Christmas Day. Officers were called to a home off of Province Lake Road in Wakefield, New Hampshire, to conduct a wellbeing check Wednesday afternoon and found the adults residents had died from suspected carbon monoxide poisoning, according to authorities. The victims have not been identified, and their exact cause of death remains under investigation. Meanwhile, New Hampshire State Fire Marshal Sean Toomey urged everyone to make sure their homes are equipped with working carbon monoxide detectors. Carbon monoxide is an odorless, colorless gas that, if inhaled, can cause sudden illness or death, according to the U.S. Centers for Disease Control and Prevention (CDC). More than 400 Americans die from carbon monoxide poisoning each year, the CDC said, while more than 100,000 visit the emergency room for treatment. Symptoms of carbon monoxide poisoning come on suddenly and typically include headaches, dizziness, weakness, upset stomach, vomiting, chest pain and confusion. Breathing in too much carbon monoxide can make you pass out or kill you, according to the CDC, which is why those who are sleeping typically die before ever experiencing symptoms. The best way to reduce the risk of carbon monoxide poisoning in your home is to make sure there are working detectors in each bedroom. It is highly recommended that homeowners put new batteries in their carbon monoxide detectors twice a year, specifically in the spring and fall while changing their clocks. Carbon monoxide detectors should also be replaced every five years. Heating systems and water heaters, as well as other gas, oil or coal burning appliances, should be regularly serviced to prevent carbon monoxide fumes from escaping into your home. Cars and trucks produce carbon monoxide as well, which is why you should never leave your vehicle running in a closed garage, especially one that's attached to a house. Close Thanks for signing up! Watch for us in your inbox. Subscribe Now Daily Roundup SIGN UP NOW